Pages

Saturday, 17 April 2010

Tech Report: Alan Wake Not Rendered In HD

Earlier this week we sighted Remedy Entertainment’s Alan Wake as one of our top five technically accomplished games for 2010, a position backed up by the game’s impressive use of dynamic lighting, particle and transparency effects, whilst of course having 4x multisampling anti-aliasing adding to the already impressive technical prowess held the title.

However, that statement is looking partially shaky, particularly because the game has now been confirmed to no longer be running 720p high definition, but instead in an unimpressive sub-HD resolution, actually lower than what some standard definition DVDs are presented in.

Yesterday, some direct feed screenshots were released by Dutch site Videogameszone believed to be from a compressed video source, and showing the game as having a 547p resolution (960x547 to be exact). However, the screenshots in question show scenes not actually in the compressed video they were believed to have come from, instead originating from what looks like compressed framebuffer grabs directly from an Xbox 360 console.

Earlier today, these screenshots were properly identified as compressed framebuffer grabs from an actual 360, and have also been confirmed to be rendering at 960x540, and then upscaled to the full 1280x720 standard HD resolution.

So the question is, why is the game’s resolution so low, and why did Remedy change it from rendering in their originally intended 720p?

Well, it may just come down to their use of A2C for certain transparencies and their need to use 4xMSAA in order to make them look good. According to Remedy the use of 4xMSAA is vital for decent ‘alpha blending’ of the A2C transparency effects, which is required to reduce texture shimmering and transparency dithering caused by using A2C instead of the more traditional, and bandwidth heavy ‘alpha coverage’.

“We like 4xAA. Due to the alpha-to-coverage feature on the Xbox 360 GPU, it's one of the key reasons we can render a lot of "alpha test" foliage like trees and bushes without them starting to shimmer or dither (as alpha-to-coverage with 4xAA effectively gives us 5 samples of alpha "blend" without actually using alpha blend).”

In addition to this, using a lower resolution like 540p allows the developers to continue to use 4xMSAA along with all the intensive framebuffer effects, and geometry hungry tessellation features which usually put a strain on rendering performance, not to mention bandwidth (tessellation excluded). And since the game was already suffering from bouts of terrible screen tearing, it could have looked like the best possible choice in order to secure relatively decent performance from the game engine in demanding scenarios. After all, having the screen tear does less for reducing image quality than a constantly fluctuating framerate, although somewhat more distracting to some people, myself included.

Essentially, rendering at 960x540 with 4xMSAA would allow then to gain a lot of performance back from when they were still rendering in 720p with either 2xMSAA or 4x. This way they could ensure a smooth 30fps update most of the time whilst reducing overall screen tearing, although recent videos confirmed to be using this new rendering resolution still have a lot of tearing going on.

By using 4x anti-aliasing Remedy have reduced the jagged look associated with sub-HD resolution upscaling, and instead provided the game with a much smoother, blended appearance. Sharpness however, is lost as a result, and although some have said that this new blurrier look adds extra atmosphere to the game, it also makes a large dent in overall image quality. Certainly, compared to the clean looking 720p direct-feed screenshots of the past, these recent sub-HD ones make the game look much less impressive in stills. Hopefully in motion, and using the uncompressed video output of the 360 console, they won’t look quite so poor.

IQGamer will be taking a closer look at the technology used in Alan Wake around the time of the game’s release. Until then we shall keep you fully updated on this story, and shed light on more details as soon as we know about them.

The original 960x547 resolution was first discovered by MazingerDUDE on NeoGAF late last night, and the final 960x540 resolution was confirmed by Quaz51 earlier this evening.

2 comments:

They haven't official confirmed that the game isn't rendereing in 720p, however the HUD in all the screnshots is native 720p whilst the actual game is not.

It is also possibe to determine the original rendering resolution when the original resolution has been downsampled, or downscaled to a lower one. Pixel counting reveals all, so long as though the screenshots aren't too compressed, which in this case they clearly aren't.

Latest Features/Editorials

About Us

Welcome to IQGamer. We started this blog as a beginning to something different. A new kind of games site, representing not only what we hope will become one of the definitive sources for the most in-depth technical analysis around, but also a fresh way of thinking when approaching conventional videogame journalism.

We’ll still be reviewing the games, and hunting down news stories. However we will also be providing you with accurate head-to-head comparisons and in-depth tech reports, along with intelligent discussions on subjects surrounding much of the industry and the wider media in which it transends.